Japanese Zero vs Spitfire vs FW 190 (5 Viewers)

[BiffF15]

It's great fun talking and reminiscing about muscle car and hotrod engines, but let's not forget, they're a whole different animal in a whole different ecosystem from a fighter engine. Let's not draw too many parallels, as their performance demands and operating profiles are so radically different, especially if the aircraft is constant speed equipped.
No automotive engine, even a Ferrari or Alfa at Le Mans, is required to run continuously at such a high percentage of its peak output as a fighter engine. OTOH, instantaneous revving response is nowhere near as critical in a fighter as in a race car.
Cheers,
Wes

Wes,

Totally agree with all the above. My point was to parallel what Allison did with the later cranks to what Ford did with the 289 HiPo to insure better operation under higher stress. I get the aircraft power plant, particularly in fighters, was a hot rod engine pushing the boundaries of performance limited by reliability.

Cheers,
Biff

 

[GrauGeist]

Agreed.
There can be a direct comparison between combat aircraft engines and "hotrod" engines, because no one ever worried about WEP or RoC in their 172...

 

[XBe02Drvr]

Agreed.
There can be a direct comparison between combat aircraft engines and "hotrod" engines, because no one ever worried about WEP or RoC in their 172...

True enough, but there sure were times I wished that old T34 had a few more ponies under her hood!

 

[BiffF15]

True enough, but there sure were times I wished that old T34 had a few more ponies under her hood!

I haven't flown a T34 but have heard they are fun!

Previously you made a comment on about rev response in a fighter wasn't as critical. The thing I'm leery of is how much throttle jockeying actually went on. There are places in a fight where either the offender or the defender will / can greatly change the nature or outcome by moving their left hand.

If you are defensive with an adversary established in the "riding" position then you need to cause him a closure problem while jinking to avoid lead poisoning. Leaving your power up makes his problem easier. I've watched enough gun footage of guys overshooting to know the offender, on either side, was either in the hit and run mode or in the unrecognized closure mode, AKA buck fever. I can't imagine with the adrenal level for guys in the middle of a massive life or death battle, especially after the minimal level of preparation they received, not doing simple things wrong like controlling closure. Or was that the way they were taught. I don't know or have a guy I could sit down with a ask.

In today's fights there are / is quite a bit of moving the throttles, I just don't know how much was done back in the day. Today, if you are pulling back on the trigger then most of the time you are pulling back on the throttles.

Cheers,
Biff

 

[Shortround6]

Once you had constant speed props, assuming the prop responded well, the engine rpm should NOT change that much.
Speed would be varied by the propeller responding to the load on it and power (that means boost for most of these engines) supplied. Cut back on "throttle" and boost drops and propeller adopt finer pitch (less speed for the same engine rpm) while the engine stays at the same rpm. Open the throttle (more boost/power) and the prop moves to course pitch and higher speeds. Obviously this has limits but once in combat the engine RPM is not going to drop to long range cruise rpm almost regardless of what the airplane/pilot are doing.
If the pilot is bounced while in economical cruise all bets are off. however getting that 400lb prop to rev up from 1000rpm to 1500rpm (assuming a 2:1 reduction gear) is a bigger problem than the rotating/reciprocating masses inside the engine.

This is my opinion, Pilots with real world experience are more than welcome to correct me. But this propeller thing is a major difference between piston engine aircraft and ground vehicles.

 

[XBe02Drvr]

I haven't flown a T34 but have heard they are fun!
Previously you made a comment on about rev response in a fighter wasn't as critical. The thing I'm leery of is how much throttle jockeying actually went on.

Those guys didn't have the energy to burn that you superjocks have. Once the surly bonds of earth were loosed, dancing the sky on laughter silvered wings bled off energy faster than it could be replenished. Adrenalated and imbued with "speed is life", a low time combat pilot would likely find it counter intuitive to deliberately sacrifice some in the middle of a furball. A lesson that the overweight, underpowered T34 taught me. It's a blast to fly, but hemorrhages energy like a slashed carotid in aerobatics. There's an STC to bolt a 285 HP IO520 on in place of the stock 225 HP O470, and that's what the airshow performer T34s have. Those extra 60 ponies are something to salivate over.

If the pilot is bounced while in economical cruise all bets are off. however getting that 400lb prop to rev up from 1000rpm to 1500rpm (assuming a 2:1 reduction gear) is a bigger problem than the rotating/reciprocating masses inside the engine.

SR6, thanks for the lucid clarification of prop/engine behavior in dynamic energy situations. In discussing this I tend to assume some things are self evident, and fail to explain in sufficient detail.
In the case of the surprise bounce, the adrenalated young pilot's first response is likely to be "balls to the walls", bending throttle, prop, and mixture levers over their forward stops, while the engineers back at Alison and Pratt and Wright cringe at their drafting tables.
So what happens? The engine gets a huge slug of rich mixture (which the pressure carb meters to an acceptable rate), and the prop governor's flyweights are seeking a higher RPM. This drives the prop blades to lower pitch, reducing aerodynamic rotational resistance and dedicating nearly all of the rapidly increasing engine torque to accelerating the rotating mass toward the new RPM setpoint. As the setpoint is approached, the pressure generated by the flyweights is taken up more and more by the control actuating spring and less and less by the propeller hydraulic control valve, causing the blades to drift toward a coarser pitch and aerodynamic rotational resistance to absorb more and more of the engine's torque. IF the damping of the governor is correct, rotational resistance and engine torque will come gracefully into balance at rated engine RPM. That and $10.79 will buy you an 8 oz coffee at any Starbucks in the nation. In practice, what you're likely to get in the mad scramble of a bounce turned furball is RPM overshoots and undershoots until the prop and governor catch up with themselves, and a mandatory report to your crew chief if you had the presence of mind to observe the overspeed excursion. (But don't get your posterior perforated while staring at the tach!)
Cheers,
Wes

 

[BiffF15]

Those guys didn't have the energy to burn that you superjocks have. Once the surly bonds of earth were loosed, dancing the sky on laughter silvered wings bled off energy faster than it could be replenished. Adrenalated and imbued with "speed is life", a low time combat pilot would likely find it counter intuitive to deliberately sacrifice some in the middle of a furball. A lesson that the overweight, underpowered T34 taught me. It's a blast to fly, but hemorrhages energy like a slashed carotid in aerobatics. There's an STC to bolt a 285 HP IO520 on in place of the stock 225 HP O470, and that's what the airshow performer T34s have. Those extra 60 ponies are something to salivate over.

Cheers,
Wes

Wes,

While I haven't done BFM / dogfighting in a piston engine warbirds, I have in the OV-10, AT-38, and F-15. Near even power results are all about the same, groveling at the floor most of the time. Excess power allows you to make / regain energy faster (fighting an F16 this is very apparent).

The biggest shortfall those guys had in WW2 was, in my opinion, proper combat training. As the war went on things like Clobber College was introduced as well as combat experience flowing back into the fighter training units.

Speed is life is a good rule of thumb. Except when it isn't. It works well for the new guy, as well as mirror BFM (do what the other guy is doing as it neutralizes him) until you get some experience under your belt.

Cheers,
Biff

 

[Ivan1GFP]

In the case of the surprise bounce, the adrenalated young pilot's first response is likely to be "balls to the walls", bending throttle, prop, and mixture levers over their forward stops, while the engineers back at Alison and Pratt and Wright cringe at their drafting tables.
So what happens?

In the case of a P-38 Lightning on a high altitude escort mission, there was a pretty fair chance there would be the sound of detonation, a bit of clanking, perhaps a connecting rod out the side or some other catastrophic failure as the fuel that had fallen out of suspension suddenly reached the engine.

=^(

 

[XBe02Drvr]

Excess power allows you to make / regain energy faster (fighting an F16 this is very apparent).

This is the big difference between modern and WWII fighters, the huge amount of excess power today's jets have. Quick recovery makes yielding a little energy to gain a tactical advantage a little less dangerous.

The biggest shortfall those guys had in WW2 was, in my opinion, proper combat training. As the war went on things like Clobber College was introduced as well as combat experience flowing back into the fighter training units.

BINGO! Chuck Yeager: "In fighter combat, the pilot with the most experience will win."

In the case of a P-38 Lightning on a high altitude escort mission, there was a pretty fair chance there would be the sound of detonation, a bit of clanking, perhaps a connecting rod out the side or some other catastrophic failure as the fuel that had fallen out of suspension suddenly reached the engine.
=^(

Everyone says the P38 was a complex difficult aircraft for a tyro pilot to handle in battle. I don't know the details, but I'm guessing this is one bird that required a little restraint in its throttle jockeying, a difficult thing for a low timer to handle in the scramble of a surprise bounce.
In a Lightning you're not likely to hear the detonation or the clanking of a failing engine over the wind and propeller noise and through the muffling effect of the turbocharger. You will certainly feel it in the form of vibration and asymmetric thrust.
Cheers,
Wes

 

[BiffF15]

This is the big difference between modern and WWII fighters, the huge amount of excess power today's jets have. Quick recovery makes yielding a little energy to gain a tactical advantage a little less dangerous.


BINGO! Chuck Yeager: "In fighter combat, the pilot with the most experience will win."


Everyone says the P38 was a complex difficult aircraft for a tyro pilot to handle in battle. I don't know the details, but I'm guessing this is one bird that required a little restraint in its throttle jockeying, a difficult thing for a low timer to handle in the scramble of a surprise bounce.
In a Lightning you're not likely to hear the detonation or the clanking of a failing engine over the wind and propeller noise and through the muffling effect of the turbocharger. You will certainly feel it in the form of vibration and asymmetric thrust.
Cheers,
Wes

Wes,

About two years ago while doing trading for my airline I was assigned a retired A10 guy for an IP. We were talking and he and a Eagle bud both had RV type planes and were regularly doing BFM. His plane was slightly better however he said the Eagle guy always seemed to win or have more energy at the end of a fight. I think he wanted me to go up in his pit and watch/ pass pointers.

While planes have increased dramatically in to thrust to weight I don't think the fighting has changed that much if the only weapon is a gun. I liken props doing BFM as "slow motion" fighting not really due to aircraft speed but to the rate at which things happen.

To the A10 guy things weren't that much slower, but to the Eagle guy they were probably noticeably so. Also one guy had many more fights under his belt. Experience counts.

Cheers,
Biff

 

[XBe02Drvr]

We were talking and he and a Eagle bud both had RV type planes and were regularly doing BFM.

If I were going to go out and do ACM in an RV or any other homebuilt, it would only be one in which I had personally cut every piece of metal, made every weld, and driven every rivet. And I would be wearing a chute I had personally jumped before and had personally packed under the supervision of the local skydive club's professional rigger.
The days of young and foolish are ancient history.
Cheers,
Wes

 

[SaparotRob]

Newbie alert.
What are: BFM
IP
ACM
RV?
Your patience is appreciated.

 

[swampyankee]

Newbie alert.
What are: BFM
IP
ACM
RV?
Your patience is appreciated.

ACM = Air Combat Maneuvers
BFM = Basic Fighter Maneuvers
RV is one of a a series of homebuilt|kit aircraft produced by Van's Aircraft
IP can be Intercept Profile, Instructor Pilot, or Initial Point.

Note that I'm not 100% certain of those interpretations.

 

[SaparotRob]

Thanks yet again.

 

[BiffF15]

Swampyankee is completely correct. BFM is dogfighting's modern name.

Cheers,
Biff

 

[SaparotRob]

I never doubted it!

 

[XBe02Drvr]

Swampyankee is completely correct. BFM is dogfighting's modern name.

Except, I still keep hearing tailhookers calling it ACM.
Cheers,
Wes

 

[BiffF15]

Except, I still keep hearing tailhookers calling it ACM.
Cheers,
Wes

There's more of us than them!

It's just like aspect, both are branches of the same military yet it's completely opposite. However, when you pass someone going in the opposite direction on a two lane road it's referred to as passing someone 180 out. Or 18 aspect. Except in the USN it's called zero aspect. Makes sense to me, said no one EVER!

So much for standardization...

Cheers,
Biff

 

[Elvis]

I thought an RV was a Recreational Vehicle...actually, if you think about it, it kinda goes hand-in-hand with the Van's aircraft definition.

 

[XBe02Drvr]

when you pass someone going in the opposite direction on a two lane road it's referred to as passing someone 180 out. Or 18 aspect. Except in the USN it's called zero aspect. Makes sense to me, said no one EVER!

You guys just don't get it. You don't seem to understand decks and overheads, and ladders and bulkheads and port and starboard either.
If your soon-to-be victim is coming at you from dead ahead, he/she/it bears 0 degrees relative, thus zero aspect. If 180 aspect, better check your six!
Cheers,
Wes